Editors' note Monday, 12:55 p.m. ET: Since this story was first published, we have added material from another former student and former law clerks of Gorsuch, as well as more information about Jennifer Sisk's political affiliations. On Tuesday, Gorsuch disputed the allegation himself during his confirmation hearing and explained the lesson he intended to teach.

A former law student of Judge Neil Gorsuch, President Trump's nominee for the U.S. Supreme Court, alleges that in a course she took from Gorsuch at the University of Colorado Law School last year, the judge told his class that employers, specifically law firms, should ask women seeking jobs about their plans for having children and implied that women manipulate companies starting in the interview stage to extract maternity benefits.

The concerns were shared in a letter, posted Sunday evening by the National Employment Lawyers Association and the National Women's Law Center, written by Jennifer Sisk, a 2016 graduate of the University of Colorado Law School. It was sent on Friday to the chairman of the Senate Judiciary Committee, Sen. Chuck Grassley, R-Iowa, and Ranking Member Sen. Dianne Feinstein, D-Calif.

Sisk, once a staffer for former Democratic Sen. Mark Udall of Colorado and the Interior Department during the Obama administration, told NPR that she wrote the letter "so that the proper questions could be asked during his confirmation hearings," which begin Monday before the Senate Judiciary Committee.

Another student in the class has disputed the account in a letter to the committee, and several women who worked for Gorsuch as law clerks have stepped forward in his defense.

On April 19, 2016, Sisk wrote, Judge Gorsuch used a hypothetical from the prepared material for the class, in which a female law student applies for jobs at law firms because the student has a large debt to pay off. The student also intends to have a family with her husband.

"He interrupted our class discussion to ask students how many of us knew women who used their companies for maternity benefits, who used their companies to — in order to have a baby and then leave right away," Sisk said.

She recalled that few students raised their hands and Gorsuch became animated. "He said, 'Come on, guys. All of your hands should be up. Many women do this,'" Sisk said.

Sisk offered overall praise of Gorsuch as a teacher and legal mind, outside of this incident.

This characterization is being disputed by Will Hauptman, a current law student at the University of Colorado. Hauptman wrote a letter to the Senate Judiciary Committee with his account on Sunday.

"Although Judge Gorsuch did discuss some of the topics mentioned in the letter, he did not do so in the manner described," Hauptman writes.

He continued, "The judge was very matter-of-fact in that we would face difficult decisions; he himself recalled working late nights when he had a young child with whom he wished to share more time. The seriousness with which the judge asked us to consider these realities reflected his desire to make us aware of them, not any animus against a career or group."

A group of 11 female former law clerks for Gorsuch also submitted a letter to the committee in support of the nominee.

"We each have lived long enough and worked long enough to know gender discrimination when we see it. Some of us have experienced it professionally on occasion," they write. "When we collectively say that Judge Gorsuch treats and values women fairly and without preference or prejudice based on their gender, we do not say that in a vacuum. We say it with the perspective of those who know that unfortunately, even in 2017, female lawyers are not always treated as equals."

The letter goes on to detail how the former clerks say Gorsuch mentored them in their careers. "The judge has spoken of the struggles of working attorneys to juggle family with work obligations; not once have we heard him intimate that those struggles are, or should be, shouldered by one gender alone," they write.

Law professors often ask provocative questions in the course of teaching. When asked if that's what Gorsuch may have been doing, Sisk told NPR: "It wasn't what he was doing. This was second-to-last class, hadn't been the style he had been using to sort of raise issues all class, or all semester."

She added, "He kept bringing it back to that this was women taking advantage of their companies, that this was a woman's issue, a woman's problem with having children and disadvantaging their companies by doing that."

Federal law prohibits employers from making hiring decisions based on pregnancy status or family plans. Sisk alleges that Gorsuch said, in Sisk's words, "Companies have to ask these sort of questions at the interview so that companies can protect themselves."

The law does not explicitly ban the asking of such questions, according to guidelines published by the Equal Employment Opportunity Commission. But if questions concerning pregnancy or family plans are asked, hiring decisions cannot be based on the answers.

In refuting this account, Hauptman writes to the committee that if Gorsuch had made such comments, "I would remember — the statements would have greatly upset me."

Sisk says school officials told her they believed Gorsuch's interpretation was wrong.

When Sisk brought these concerns to University of Colorado Law School senior assistant dean of students Whiting Leary and then-dean Phil Weiser, they said they would speak to Gorsuch at the end of the term. Sisk did not follow up with the school about whether those conversations happened. Leary and Weiser did not respond to calls from NPR.

When asked what steps she would have liked to see the school administration take, Sisk recalls saying, "I had no interest in having him stop teaching. I did think he was a good professor. But my interest is more with having someone talk to him and explain to him why he shouldn't be making these comments in class, why he needed to understand what the state of employment law was, and why it was problematic for him to express this view of employment law to a class full of students."

Sisk says one of the reasons she spoke up was because of hearing stories of discrimination from her mother, who she says attended law school in the 1970s.

"It seemed to me that was in the past," Sisk said. "So I was surprised sitting in this class, hearing this in April of 2016, and thinking that even a professor that I respected, that I see as so bright, so well-versed in the law, could also not only hold these views, but was so comfortable expressing them to a room full of law students, including female law students that he the same semester had offered to mentor."

When she heard these allegations, former Gorsuch law clerk Janie Nitze told NPR, "I didn't know whether to laugh or cry." Nitze clerked for Gorsuch in 2008-2009, and was one of the 11 former female clerks to sign on to the letter sent to the Senate Judiciary Committee on Monday.

In a statement, Nitze says, in part, "the Judge is usually the first person I go to for career advice. And the first words he has for me when I do are: 'What can I do to help you?' The suggestion that he 'discounts the worth of working females' is patently absurd."

The National Women's Law Center, in posting Sisk's letter to the Judiciary Committee, cited a 2003 opinion written by the late Chief Justice William Rehnquist upholding gender-neutral application of the Family Medical Leave Act by arguing against the "presumption that women are mothers first, and workers second." Rehnquist went on to write, "These mutually reinforcing stereotypes created a self-fulfilling cycle of discrimination that forced women to continue to assume the role of primary family caregiver, and fostered employers' stereotypical views about women's commitment to work and their value to employees."

Sisk raised these concerns publicly in a posting on Facebook in late January, shortly after Gorsuch was nominated by Trump to the high court. After stating the claims outlined later in her letter, Sisk also said, "He's still better than the rest of the choices."